Disk carbon for arc lamps



(No Model.)

H. 'W. LIBBEY. DISK CARBON FOR ARC LAMPS.

No. 471,526. Patented Mar. 22, 1892.

UNITED STATES PATENT ()FFICE. I

HOSEA W. LIBBEY, OF BOSTON, MASSACHUSETTS.

DISK CARBON FOR ARC LAMPS.

SPECIFICATION forming part of Letters Patent No. 471,526, dated March 22, 1892. Application filed October 17, 1890. Serial No. 368,445. (No model.)

To all whom it may concern.-

Be it known that I, HOSEA W. LIBBEY, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain newand useful Improvements in Disk Carbons for Are Lamps, of which the following, taken in connection with the accompanying drawings, is a specification.

In arc lamps where disk carbons are employed it has hitherto been very difficult, if

i not impossible, to produce a disk carbon that will be consumed evenly all round, thus rendering the light unsteady. Now, the object of my invention is to overcome this defect and to produce a spirally-coiled disk carbon that will consume evenly.

The invention consists of a spirally-coiled disk carbon having a spiral beveled perimeter and a spiral V-shaped groove on both sides, as hereinafter fully described, and pointed out in the claims.

Referring to the accompanying drawings, Figure 1 represents a side view of a disk carbon embodying my invention. Fig. 2 is a section taken on line m m of Fig. 1. Fig. 3 is a side view of a modified form of disk.

The perimeter of the disk carbon A is of spiral form, beveled as shown-that is, a spiral whose coils have a gradually-decreasing diameter--so that from the point a,.where the spiral commences, to the point I), where it-ends after passing once round, is represented the exact amount of carbon that will be consumed at one revolution of the carbon, and so on for each revolution until the carbon has been consumed. By means of the spiral V-groove the carbon will burn as long as there is any sub stance between the outer line of the spiral and the next adjacent line; but as soon as this portion of the carbon has been consumed the carbon will be caused to rotate, so as to keep its outer edge in contact with the other electrode.

B is a hole in the center of the carbon for mounting it upon the carbon-holder that is to provided on. one or both sides with annular grooves.

Although I have describedand prefera V- shaped groove, any other shaped groove might be employed; or the groove might be formed on one side only, if desired, without departing from my invention.

What I claim as my invention is- 1. A disk carbon the perimeter of which is of spiral form, substantially as set forth.

2. A disk carbon havinga spiral groove on each side, substantially as and for the purpose set forth.

3. A disk carbon the perimeter of which is of spiral form and having a spiral groove, substantially as set forth.

4. -A disk carbon having a groove or grooves on one or both sides, whereby the amount of carbon consumed is regulated so that the carbon will burn equally all round, substantially as set forth.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, on this 30th day of September, A. D. 1890.

HOSEA W. LIBBEY.

Witnesses:

CHAS. STEERE, EDWIN PLANTA. 

